"We -- I'm talking about several of our financial and media organisations, state institutions and critical infrastructure -- have been under attack for several years," Kremlin spokesman Dmitry Peskov said.

The cyberattacks "come from various Western countries, including the US," he added.

Peskov said that President Vladimir Putin had "several times suggested to Washington and his American counterpart to work together in the field of cybersecurity. These suggestions have been rejected by our American colleagues."

The Times at the weekend reported current and former government officials describing the classified deployment of American computer code inside Russia's power grid and other targets.

The action is intended partly as a warning but also to leave the US poised to conduct cyberstrikes in the event of a major conflict with Russia, the newspaper said.

US President Donald Trump reacted with fury to the report, calling it on Twitter a "virtual act of Treason" and rejecting the paper's claims.

The Times report came after an investigation by US special counsel Robert Mueller of alleged hacking by Russia's GRU intelligence agency and social media manipulation by Russia's Internet Research Agency to benefit Trump's election campaign.